Self-feeding or stoker furnace.



PATENTED JULY 1'7, 1906.

I. E. SMALL. SELF FEEDING 0R STOKER FURNACE.

APPLICATION FILED NOV. 10, 1904.

UNITED STATES PATENT ()FFIGE. i

Specification of Letters Patent.

Patented July '1' 7, 1906.

Application filed November 10,1904. Serial No. 232,103.

To all whom, it natty concern:

Be it known that I, FRANK E. SMALL, a citizen of the United States, and a resident of the borough of Brooklyn, inthe city and State of New York, have invented a new and useful Self-Feeding or Stoker Furnace, of which the following is a specification.

My invention relates to a self-feeding or stoker furnace, with. the object in view of utilizing air under pressure rather than steam to induce a forced draft and support combustion.

In the accompanying drawings, Figure 1 is a vertical longitudinal'section of so much of a furnace as will sufiice to show a practical embodiment of my invention, and Fig. 2 is a horizontal section of the same in the the line A A of Fig. 1.

' The number of bars which compose what I am pleased to term a section is here shown as twenty-three; but this number is not important to my present invention and may be increased or diminished at pleasure-.- The several bars are quite similar inv their structure, so that the description of one may serve for all.v They are mounted independently side by side and rest at their lower ends on a footblock 1 and at their upper ends on a headblock 2. These blocks 1 and 2 are made hollow, the foot-block 1 serving as a temporary ash-receptacle, while the head-block 2 serves as an air-box for distributing the air to the grate-bars.

A grate-bar is denoted as a whole by 3. It is provided with a stepped face i,- the treads of the steps being provided with manifold perforations 5, through which the air from within the bar passes into contact with the products of combustion.

It is intended that the threads of the stepped face shall be about horizontal when the bar is resting in the diagonal position shown in Fig. 1, and each bar is permitted a limited longitudinal reciprocating movement on its foot and head blocks 1 and 2. This limited longitudinal movement is imparted to the bar by means of a link 6, connecting the under side of the bar with an arm 7 on a rock-bar 8, eictending transversely across the support at the front of the furnace and ed by any well known or approved means. i

It is intended that adjacent bars shall be reciprocated simultaneously in opposite directions, and to this end the arm- 7 on the rock-bar 8, connected with the bar 3 by the plane oflink 6, is set at such an angle to an adjacent arm- 9 on the rock-bar 8 that when the bar 8 is rocked in one direction it will push on the link 6 and draw on the adj acent link 10, connecting an adjacent bar with the arm 9, and when the bar 8'is rocked in the opposite di rection it will push on'the link 10 and draw on the adjacent link 6.-

The fuel is fed into a ho per 11 and is forced from the bottom of tlie hopper onto the stepped faces of the grate-bars by means of abutments 12, one permanently fixed on each bar at the upper. forward end of the bar, these abutments serving, together with portions of the bar immediately in advance of them, to form the bottom of the hopper, a space 13 being left "at the lower rear wall of the hopper for the fuel to pass through onto the grate-bar. r

- The lower part of the upper end of the bar is provided with an opening 14, which registers with an opening 15in the top of the airboX or head-block, so that air may be per-- mitted to pass from within the head-block 2 up through into the grate-bar, the opening 15 being sufficiently long tokeep the communication between the interior of the headblock and the interior of the bar established during the entire reciprocatory movement of the bar.

Each bar is furtherprovided with a steam-' jet nozzle 16, set in its forward end for the purpose of attaching a steam-hose thereto to blow the ashes and any'foreign accumulations out of the interior of the bar,and the same nozzle may also serve in the event of the air-supply failing for any purpose to inject steam or steam and air into the bar to support combustion.

At its lower rear end the grate-bar is provided with an opening 17 in its bottom wall or base, which registers with an opening 18in the top of, the hollow foot-block 1, through which the ashes which may fall through the perforations in the treads of the stepped face of the bar may pass into the interior of the footblock and thence slide along down its inclined wall 19 and thence by means of a sliding gate 20 may be allowed to fall into an ash-pit below the grate-barsv A portion of the air from the bar is also permitted to pass through an opening 21 in the slanting wall 19 of the foot-block 1 into the space beneath the stationary perforated grate-bar 22, onto which the unconsumed cinder falls from the moving grate-bars, and

this serves to supply air to the glowing cinder on the stationary grate-bar to complete the combustion before the cinder finally falls off ficient pressure against the door 24 to cause it to swing open and permit the body of ash and cinder to slide down into the asn-pit,

27, into which the when the door 24 under the influence of gravity will swing back again into its normal 1 position and there remain until the pressure of accumulated ash and cinderagain opens 1t..

It is found desirable to direct the ashes which fall from the interior of the hollow grate-bars into a pit 26 separate from the pit ash and cinder falls from the stationary grate-bar, because the ash from the interior of the grate-bar is found to be rich in carbon and may be again utilized to great advantage as fuel.

. ir under pressure may be supplied to the head-block 2, on which the upper ends of the grate-bars rest, through hollow supportingcolumns 28 111 communication with a supplypipe 29, leading to a suitable supply of air under pressure.

What I cla1m'is- 1. The combination with inclined hollow I grate-bars having their faces perforated, and

means for reciprocating them longitudinally,

I a stationary grate-bar located at the lower ends of the inclined bars and provided'with perforations in its face and an air-chamber beneath the stationary bar, of means for sup plying fluid under pressure to the interiors of the hollow inclined bars and thence to the chamber beneath the stationary bar and means for feeding fuel ontothe inclined bars.

'2. The combination with inclined, hollow grate-bars having their faces perforated and means for reciprocating them longitudin ally, of a stationary grate-bar located at theilower ends of the inclined grate-bars and having perforations in its face, an air-chamber beneath the stationary bar, means for directing the ashes from within the reciprocatingbars into an ash-pit, means fordirecting the ashes from the stationary bar into a separate ash-pit, means for supplying fluid under-pressure to the interior of the hollow bars and thence to the chamber beneath the stationary bar and means for feeding fuel onto the inclined bars. I p

3. The combination with inclined, hollow grate-bars having their faces perforated and 'means for reciprocating them longitudinally,

the said bars being provided with openings in their lower ends, ofan ash-receptacle in communication with the s'aidopen-in'gs; a stationary bar at the lower ends-of the inclined barshaving perforations in its face, an airchamber beneath the stationary bar, the said ash-receptacle being provided. with an opening through to the chamber beneath the stationary bar, means for supplying air, under pressure to the interior of the reciprocating hollow bars and'means for feeding fuel onto the bars.

In testimony that I claim the foregoing as my invention I have signed my name, in pres ence of two witnesses, this 7th day of November, 1904. l g a FRANK E. SMALL.

Witnesses FREDK. HAYNES, HENRY THIEME. 

